1. Field of the Invention
The present invention relates to a washing machine, and more particularly to a washing machine having a spraying nozzle assembly which not only can evenly spray a circulated washing liquid onto articles to be washed, but also can effectively dissolve a detergent, thereby improving the washing efficiency.
2. Prior Arts
Generally, a washing machine is an appliance for separating dirt from articles to be washed such as clothing by sequentially carrying out various cycles in the order of liquid feeding, washing, rinsing, dehydrating, and draining cycles.
While the above cycles are being executed, dirt contained in the clothing separates from the clothing by means of detergents or by means of friction between the washing liquid and the clothing.
However, in conventional washing machines, detergent particles cannot completely dissolve in the washing liquid while the washing cycle is being executed, so some of the detergent particles remain in a space formed between a spin tub and an outer tub in its solid state. For this reason, the dirt does not easily separate from the clothing and a large quantity of detergents are required for cleaning the clothing.
Further, conventional washing machines repeat the liquid feeding and draining cycles several times in order to carry out the washing and rinsing cycles, so they unnecessarily waste the washing liquid.
In order to overcome the above problems, various types of conventional washing machines which reduce a required amount of the detergent by completely dissolving the detergent in the washing liquid and prevent the washing liquid from wasting by re-using the washing liquid by circulating the washing liquid through a circulation pump, have been proposed.
U.S. Pat. No. 5,285,664 issued to Chang et al. discloses such a conventional washing machine.
FIG. 5 shows Chang's washing machine 500.
As shown in FIG. 5, Chang's washing machine 500 comprises a housing 12 having a control panel 11 at its upper portion, and an outer tub 15 disposed in housing 12 so as to receive the washing liquid. A spin tub 512 is accommodated in outer tub 15 and is formed at its side wall with a plurality of through holes 511. Washing machine 500 also has a motor 17 which generates a driving force for operating washing machine .cndot., and a power transmission 540 for transmitting the driving force from motor 17 to spin tub 512. A circulation pump 525 is disposed at a bottom of housing 12 in such a manner that it can communicate with outer tub 15. Circulation pump 525 circulates the washing liquid through a circulation tube 521 into an adapter 520, or drains the washing liquid out of washing machine 500 through a drain tube 533.
Power transmission 540 includes a rotating shaft 542 connected to motor 17 through a belt 18 so as to receive the driving force from motor 17, a gear and link assembly 544 for rotating an agitator 548 mounted on a bottom wall of spin tub 512 in the forward and reverse directions in accordance with predetermined cycles, and a connection member 546 for connecting agitator 548 to gear and link assembly 544.
A removable lid 515 having a sprinkling guide surface 516 is mounted on an upper portion of outer tub 15, and is provided at its underside with an annular guide member 514 having a discharge silt 513. In addition, a sprinkling nozzle 518 is formed between annular guide member 514 and removable lid 515 so as to spray the washing liquid into spin tub 512.
On the other hand, circulation pump 525 has a rotating shaft 528 which is integrally formed at its one end with a pulley 529. Pulley 529 of circulation pump 525 is connected to motor 17 by means of a belt 18 in such a manner that circulation pump 525 can receive the rotational force from motor 17.
The conventional washing machine having a construction as described above operates as follows.
Firstly, when a user pushes an operating button installed on control panel 11, the washing liquid is introduced from a liquid source into a space 517 formed between removable lid 515 and guide member 514 by way of a washing liquid feed pipe 519 and adapter 520.
Then, the washing liquid that has been introduced into space 517 is sprinkled into spin tub 512 through discharge silt 513 of guide member 514 and through sprinkle nozzle 518 until a predetermined liquid level in spin tub 512 is achieved.
When the predetermined liquid level is achieved, a liquid feed control valve 530 blocks liquid feed pipe 519 and, at the same time, motor 17 rotates in the forward direction. The rotational force of motor 17 is transmitted to agitator 548 by way of belt 18, by way of rotating shaft 542 of power transmission 540, by way of gear and link assembly 544 and by way of connection member 546, so that agitator 548 rotates in the forward and reverse directions, thereby washing the clothing.
At the same time, the forward directional drive force of drive motor 17 is also transmitted to circulation pump 525 through belt 18, so that circulation pump 525 rotates in the forward direction while the washing cycle is being executed. Therefore, the washing liquid that has been introduced into outer tub 15 is discharged from outer tub 15 into circulation pump 525 through a discharge port 526 formed at the bottom wall of outer tub 15.
Upon receiving the washing liquid, circulation pump 525 compresses the washing liquid and draws the washing liquid up to adapter 520 through circulation tube 521. Then, the compressed washing liquid is introduced into space 517 and sprinkled to the clothing placed in spin tub 512 through discharge slit 513 and sprinkling nozzle 518.
When the washing cycle has finished, the washing liquid in outer tub 15 is drained out of washing machine 500 through draining tube 533. At this time, motor 17 rotates in the reverse direction so as to rotate spin tub 512. As spin tub 512 rotates, the clothing placed in spin tub 512 is subjected to centrifugal force so that the clothing is forced radially outward (i.e., toward the side wall of spin tub 512), and thereby, the washing liquid contained in the clothing is drained out through the plurality of through holes 452 formed in the side wall of spin tub 512.
On the other hand, when motor 17 rotates in the reverse direction, circulation pump 525 connected to motor 17 also rotates in the reverse direction, so the washing liquid discharged from the plurality of through holes 452 is drained out of washing machine 500 through circulation pump 525.
However, the conventional washing machine constructed as described above has the following disadvantages.
Firstly, the washing machine sprays the washing liquid through the sprinkling nozzle which has a relatively small size, so it takes a long time to spray a predetermined amount of the washing liquid into the spin tub.
Further, since the sprinkling nozzle is only formed at one spot of the outer tub, the washing machine does not evenly spray the washing liquid onto the clothing when the clothing is fully loaded in the spin tub.